DESCRIPTION: (Applicant's Abstract) This proposal requests a Mentored Research Scientist Development Award. Under the sponsorship of Isaac D. Montoya, Ph.D., the applicant will engage in research and didactic learning activities intended to further his professional career in the drug abuse research. In addition to Dr. Montoya, the candidate will work with Dr. David Bell to increase his understanding of structural equation modeling techniques. These techniques, along with the didactic learning activities, will facilitate the completion of a proposed research effort guided by the following general theoretical hypothesis: The roles individual cocaine users occupy within drug use networks mediate the influence of psychological functioning and social network structure on the sexual and needle risk behaviors of individual drug users. The proposed study will be conducted in two distinct stages, each of which expresses two distinct aims. These aims are: Stage 1 a. To conduct secondary analysis of the associations between psychological functioning domains, network structures, and HIV risk behaviors among participants in a NIDA-funded longitudinal study of out of treatment drug users; b. Based on results of this analysis, construct a theoretical model of the relationships between structural dimension of social networks, the network roles of individual drug users within those networks, and the psychological functioning of those individuals; Stage 2 a. Administer the SCL-90-R, a standard and reliable instrument for measuring psychological distress, to 433 participants in a currently-funded study of drug use social networks at baseline and 12 months follow-up; b. Using advanced statistical techniques, test the efficacy of the theoretical model constructed in Stage lb for characterizing relationships between psychological distress, social network structure, social network role, and sex/needle risk behavior. Results of both stages will be disseminated in the form of articles submitted to peer reviewed journals. In addition, during the final year of the grant, the candidate will be engaged in activities such as grant writing which are intended to extend and elaborate the findings of the research project.